1. Field of the Invention
The present invention relates to a rolling element screw applied in linear transmission, and more particularly to a ball screw which is provided with a rotatable sleeve on the nut, and the rotatable sleeve can be rotated by the rolling elements to drive other structures to realize the desired movement.
2. Description of the Prior Art
Conventional ball screws each are commonly provided with a nut on a screw in such a manner that when the screw is rotated, the nut will be driven to move, thus driving a working platform combined on the nut to move. Each of two opposite ends of the nut is provided with a recirculation part, and between the nut and the respective recirculation parts is disposed at least one circulating channel. Plural balls are disposed in the circulating channels. When the screw is rotated to drive the nut to move, the balls will cooperatively rolls circularly to reduce the interference between the screw and the nut and increase the lubrication effect. When the balls pass through the linear circulation hole of the nut, the moving power of the balls is in direct proportion to the rotation of the screw. Such a moving power contains a great amount of energy, so far, however, it has never been utilized, thus causing the power and energy waste.
Hence, in order to obtain and substantially utilize the power caused when the balls pass through the linear circulation hole, the inventor of the present invention has developed a new ball screw.